Role of Composition and Substrate Temperature on Nonlinear Optical Properties of GeSeTe Thin Films in 0.4–2.4-$\mu \text{m}$ Wavelength Range

Abstract

The nonlinear optical properties of Ge10Se90– x Te x ( $x = 0$ , 10, 20, 30, 40, 50) thin films have been investigated as a function of composition and substrate deposition temperatures (303, 363, and 423 K). The third-order nonlinear susceptibility and nonlinear refractive index have been estimated. Nonlinearity in refractive index increases with Te content and also with increasing substrate temperature. Among the investigated compositions of Ge10Se90– x Te x , the Ge10Se40Te50 composition shows more prominent nonlinear refractive index in comparison with pure silica. The high third-order susceptibility and nonlinear refractive index may make these materials capable for high-speed communication fibers.